1. Field of the Invention
This invention relates to a valve device for an inflatable article, more particularly to a valve device with a diaphragm that can be kept in a deflected position to maintain the valve device in an open state for facilitating deflation of the inflatable article.
2. Description of the Related Art
A conventional inflatable article is generally provided with a check valve device in an inflating port. The check valve device has a flexible diaphragm that permits air to enter the inflatable article during inflation and that closes the inflating port by virtue of the air pressure inside the inflatable article when the inflation stops. However, with such a valve device, deflation of the inflatable article is inconvenient.
There is provided another conventional valve device that includes a flexible diaphragm which has a connecting surrounding portion attached to a valve seat of a tubular member thereof such that the flexible diaphragm can be depressed to deflect from the valve seat. Two retaining flanges extend from the valve seat and are disposed adjacent to the connecting surrounding portion such that the flexible diaphragm, when depressed, abuts against the retaining flanges so as to maintain the valve seat in an open state for deflation of the inflatable article. However, only a small portion of the diaphragm in the vicinity of the connecting surrounding portion is retained by the retaining flanges, so that the diaphragm is likely to disengage from the retaining flanges and close the valve seat by a large deflating force during deflation. Therefore, the user has to depress the diaphragm repeatedly, which is very inconvenient.